Mechanism for converting rotary to reciprocating action at reduced speed



D. SPENDER 3,359,809

Dec. 26, 1967 MECHANISM FOR CONVERTING ROTARY TO RECIPROCATING ACTION AT REDUCED SPEED Filed July 25, 1966 INVENTOR. DONALD L. SPENDER ATTORNEY United States Patent MECHANISM FOR CONVERTING ROTARY T RECIPROCATING ACTION AT REDUCED SPEED Donald L. Spender, Cheshire, C0nn., assiguor to Scovill Manufacturing Company, Waterbury, Conn., a corporation of Connecticut Filed July 25, 1966, Ser. No. 567,438 4 Claims. (Cl. 74-55) This invention relates to mechanism to convert rotating to reciprocating action at reduced speed. The mechanism is useful for embodiment in power operated knives, toothbrushes and other power operated tools and appliances, for imparting reciprocatory movement to knife blades, brushes and other parts.

The main object of the invention is to convert rotary to reciprocating movement on the same axis by mechanism which includes a rigid non-tiltable swash plate. The construction is unique in its simplicity and efficient for its intended purposes.

In the drawings:

FIG. 1 is an elevational view, partly in section, of mechanism embodying my invention, showing the recipr-ocated shaft in retracted position.

FIG. 2 is a view similar to FIG. 1, showing the reciprocated shaft in extended position.

FIG. 3 is an elevational view, partly in section, of a modification of the mechanism shown in FIG. 1, showing the reciprocated shaft in retracted position.

FIG. 4 is a view similar to FIG. 3, showing the reciprocated shaft in extended position.

FIG. 5 is an elevational view of a detail of construction embodying a modification of the driving plate of FIGS. 3 and 4.

In the embodiment of the invention shown in FIGS. 1 and 2, the rotated shaft has mounted thereon a driving plate 11 provided with a ball retaining rim 12 and hub 13, the hub being keyed to the shaft 10 by pin 14 to rotate with the shaft. A support 15 has slidably mounted therein a non-rotatable shaft 16 in axial alignment with the rotated shaft 10. A rigid swash plate 17 is fixed on the shaft 16 by the hub 18 which may be integrally formed with the plate 17. The plate 17 extends at an angle of less than 90 degrees to the axis of the hub 18 and shaft 16. A coiled spring 19 surrounds the shaft 16 and bears at opposite ends on the support 15 and hub 18 of the swash plate 17.

The shaft 10 rotates the driving plate 11. A ball 20 is carried loosely by the plate 11, and under influence of centrifugal force the ball 20 travels with the plate adjacent the retaining rim 12. Due to the angular disposition of the swash plate 17 and its rigid mounting on the hub 18, the ball 20 carried by the rotated plate 11 causes the plate 17 and shaft 16 to move in an axial direction to the advanced or extended position of FIG. 2, and then permits the plate 17 and shaft 16 to move in the opposite axial direction to the retracted position under influence of the spring 19 when the ball 20 has been moved by the driving plate 11 to the position shown in FIG. 1'.

In the modified embodiment shown in FIG. 3 and 4, the shaft 30 is supported in the support 31 rotary action. A driving plate 32 with hub 33 is keyed to the shaft 30 by pin 34. A roller hub 35 free to rotate on the shaft 30 has a radially extending stub shaft 36 on which is mounted a roller 37 by the nut 38. The roller 37 is designed to peripherally contact the driver plate 32.

A support 40 slidably supports the non-rotatable reciprocated shaft 41 on one end of which is mounted a swash plate 42 provided with hub 43. A spring 44 surrounds the shaft 41 and bears at opposite ends on the support 40 and hub 43. The shafts 30 and 41 are axially aligned, with the inner end of the shaft 30 extending into a centrally located opening in the swash plate 42 and hub 43 as shown in FIGS. 3 and 4. The swash plate 42 extends at an angle of less than degrees to the axis of the hub 43 and shaft 41. The roller 37 contacts the proximate faces of the driving plate 32 and swash plate 42. The hub 35 is free to rotate on shaft 30, and the roller 37 is driven by the driver plate 32 which causes the roller 37 to roll about the edge of the swash plate 32 due to friction, resulting in moving the swash plate 42 and shaft 41 in axial direction to the extended or advanced position of FIG. 4, and then permits the plate 42 and shaft 41 to move in the opposite axial direction to the retracted position of FIG. 3 under influence of the spring 44 when the roller has been moved by the driving plate 32 to the position of FIG. 3.

FIG. 5 shows :a slightly different form of driving plate 45, pinned to the shaft 30, which may be used in place of the plate 32 shown in FIGS. 3 and 4. The angular position of the roller 37 relative to the hub 35 has been modified, whereby to increase or decrease the frequency of the reciprocation of the shaft 41.

The provision of a rigid non-tiltable swash plate for cooperating with the rotated driving plate enables me to use axially aligned drive and driven shafts, and eliminates the need of flexible connections between the swash plate and the reciprocated shaft.

Changes may be made in details of construction and form of parts without departing from the scope of the invention as defined in the appended claims.

I claim:

1. Mechanism for converting rotating to reciprocating action comprising:

(a) a rotated shaft,

(b) a driving plate fixed on and rotated with the shaft,

(c) a non-rotatable shaft mounted for reciprocating action axially aligned with the rotated shaft,

(d) a rigid non-tiltable swash plate mounted on the non-rotatable shaft at an angle of less than 90 degrees to the axis of the shaft,

(e) means urging the swash plate toward the driving plate, and

(f) rollable means between the driving plate and swash plate for moving the swash plate and non-rotatable shaft in axial direction.

2. Mechanism for converting rotating to reciprocating action comprising:

(a) a rotated shaft,

(b) a driving plate fixed on and rotated with the shaft,

(c) a support,

(d) a non-rotatable shaft mounted in the support for reciprooatory movement axially aligned with the rotated shaft,

(e) a rigid non-tiltable swash plate having a hub, the swash plate extending at an angle of less than 90 degrees to the axis of the hub, said plate and hub being fixedly mounted on the non-rotatable shaft,

(f) resilient means between the swash plate hub and rollable means is a roller rotatably mounted on a hub the support urging the swash plate and hub toward and rotated by the driving plate. the driving plate, and

(g) reliable means between the driving plate and References Cited swash plate for moving the swash plate and non- 5 UNITED STATES PATENTS rotatable shaft in axial direction. 1,759,842 5/1930 Fossa 103 213 The mfichanism fi d by claim 2, in which the 2 211 741 8/1940 Elweu 103 213 'rollable means is a ball loosely carried between the driving plate and the swash p1 ate. FRED C. MATTERN, ]R., Przmary Examzner.

4. The mechanism defined by claim 2, in which the 10 W. S. RATLIFF, Assistant Examiner. 

1. MECHANISM FOR CONVERTING ROTATING TO RECIPROCATING ACTION COMPRISING: (A) A ROTATED SHAFT, (B) A DRIVING PLATE FIXED ON AND ROTATED WITH THE SHAFT, (C) A NON-ROTATABLE SHAFT MOUNTED FOR RECIPROCATING ACTION AXIALLY ALIGNED WITH THE ROTATED SHAFT, (D) A RIGID NON-TILATABLE SWASH PLATE MOUNTED ON THE NON-ROTATABLE SHAFT AT AN ANGLE OF LESS THAN 90* DEGREES TO THE AXIS OF THE SHAFT, (E) MEANS URGING THE SWASH PLATE TOWARD THE DRIVING PLATE, AND (F) ROLLABLE MEANS BETWEEN THE DRIVING PLATE AND SWASH PLATE FOR MOVING THE SWASH PLATE AND NON-ROTATABLE SHAFT IN AXIAL DIRECTION. 